1. Field
The present invention relates to an energy absorber for use as impact protection in a motor vehicle, in particular in the region of the doors.
2. Discussion of Related Art
Impact protection of this type serves primarily to protect vehicle occupants from serious injuries in the event of a collision. Some impact protection devices serve not to absorb energy produced during impact between the motor vehicle and a corresponding collision object, for example another car, but rather to absorb energy produced in the event of a collision on the impact of a vehicle occupant on for example the inner lining of a door.
Foam pads disposed after the inner lining of a door have been used to absorb this energy and offer some protection to the vehicle occupant. Foam pads of this type have a constant density distribution. In addition, the force transmitted to the vehicle occupants continues to increase as the deformation of the foam pad increases because the foam pad can absorb less and less energy with increasing deformation.
Furthermore, the safety requirements for motor vehicles in various countries are subject to differing guidelines. In Europe, many tests are carried out based on the Euro NCAP (European New Car Assessment Programme) Guidelines, whereas in the United States, the IIHS (Insurance Institute for Highway Safety) Guideline is widely used. These guidelines define differing maximum forces to which vehicle occupants may be subjected and also differ in terms of the positions at which these maximum forces may act. Vehicle manufacturers themselves may set additional standards to be met by the energy absorber.
The typical foam pad described above defines the same maximum forces at all positions over its width due to its uniform density, rendering it incapable of fulfilling both the above-mentioned standards at the same time and those of the vehicle manufacturers. Therefore, differing foam pads are typically used for a single vehicle for differing countries in order to comply with the respective standards.
Some prior art are energy absorbers include conical or pyramid-shaped absorption elements which telescope on impact in order to absorb the energy. An energy absorber of this type is known for example from DE 39 19 742 A1 (corresponds to U.S. Pat. No. 4,890,877). Although this configuration is an improvement on the previously used foam pads, a need still exists for an improved energy absorber that can meet both of the above-mentioned guidelines and also the vehicle manufacturer requirements.